The company expects to have data from transfusion-dependent and non-transfusion dependent patients this year, with a potential expanded US approval in 2025 for Pyrukynd.

Vertex and bluebird compete for sickle cell patients, BioMarin talks about divesting Roctavian, and Sarepta warned that sales of Elevidys will plateau with a narrow label.  

The FDA would only withdraw a rare disease gene therapy for “pretty clear” reasons, such as when there is minimal benefit with extensive side effects. The one-and-done nature of administration also makes withdrawal easier, CBER Director Peter Marks says.

The drug maker said the program would allow for continued reimbursement when patients change insurance plans. A Sangamo-partnered gene therapy for hemophilia A is also in the works.